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CompareInfo.Compare Method (String, String)

Compares two strings.

Namespace:  System.Globalization
Assembly:  mscorlib (in mscorlib.dll)
'Declaration
Public Overridable Function Compare ( _
	string1 As String, _
	string2 As String _
) As Integer

Parameters

string1
Type: System.String
The first string to compare.
string2
Type: System.String
The second string to compare.

Return Value

Type: System.Int32

Value

Condition

zero

The two strings are equal.

less than zero

string1 is less than string2.

greater than zero

string1 is greater than string2.

The comparison is performed, by default, using None. If a security decision depends on a string comparison or a case change, the application should use the InvariantCulture to ensure that the behavior is consistent regardless of the culture settings of the operating system.

NoteNote

When possible, the application should use string comparison methods that accept a CompareOptions value to specify the kind of comparison expected. As a general rule, user-facing comparisons are best served by the use of linguistic options (using the current culture), while security comparisons should specify Ordinal or OrdinalIgnoreCase.

The following code example compares portions of two strings using the different CompareInfo objects:


' The following code example compares two strings using the different CompareInfo instances:
'    a CompareInfo instance associated with the "Spanish - Spain" culture with international sort,
'    a CompareInfo instance associated with the "Spanish - Spain" culture with traditional sort, and
'    a CompareInfo instance associated with the InvariantCulture.

Imports System
Imports System.Globalization

Public Class SamplesCompareInfo

   Public Shared Sub Main()

      ' Defines the strings to compare.
      Dim myStr1 As [String] = "calle"
      Dim myStr2 As [String] = "calor"

      ' Uses GetCompareInfo to create the CompareInfo that uses the "es-ES" culture with international sort.
      Dim myCompIntl As CompareInfo = CompareInfo.GetCompareInfo("es-ES")

      ' Uses GetCompareInfo to create the CompareInfo that uses the "es-ES" culture with traditional sort.
      Dim myCompTrad As CompareInfo = CompareInfo.GetCompareInfo(&H40A)

      ' Uses the CompareInfo property of the InvariantCulture.
      Dim myCompInva As CompareInfo = CultureInfo.InvariantCulture.CompareInfo

      ' Compares two strings using myCompIntl.
      Console.WriteLine("Comparing ""{0}"" and ""{1}""", myStr1, myStr2)
      Console.WriteLine("   With myCompIntl.Compare: {0}", myCompIntl.Compare(myStr1, myStr2))
      Console.WriteLine("   With myCompTrad.Compare: {0}", myCompTrad.Compare(myStr1, myStr2))
      Console.WriteLine("   With myCompInva.Compare: {0}", myCompInva.Compare(myStr1, myStr2))

   End Sub 'Main 

End Class 'SamplesCompareInfo


'This code produces the following output.
'
'Comparing "calle" and "calor"
'   With myCompIntl.Compare: -1
'   With myCompTrad.Compare: 1
'   With myCompInva.Compare: -1



The following code example demonstrates calling the Compare method.


Imports System
Imports System.Text
Imports System.Globalization

NotInheritable Public Class App
    Shared Sub Main(ByVal args() As String) 
        Dim sign() As String = {"<", "=", ">"}

        ' The code below demonstrates how strings compare 
        ' differently for different cultures.
        Dim s1 As String = "Coté"
        Dim s2 As String = "coté"
        Dim s3 As String = "côte"

        ' Set sort order of strings for French in France.
        Dim ci As CompareInfo = New CultureInfo("fr-FR").CompareInfo
        Console.WriteLine("The LCID for {0} is {1}.", ci.Name, ci.LCID)

        ' Display the result using fr-FR Compare of Coté = coté.  	
        Console.WriteLine("fr-FR Compare: {0} {2} {1}", _
                          s1, s2, sign((ci.Compare(s1, s2, CompareOptions.IgnoreCase) + 1)))

        ' Display the result using fr-FR Compare of coté > côte.
        Console.WriteLine("fr-FR Compare: {0} {2} {1}", _
                          s2, s3, sign((ci.Compare(s2, s3, CompareOptions.None) + 1)))

        ' Set sort order of strings for Japanese as spoken in Japan.
        ci = New CultureInfo("ja-JP").CompareInfo
        Console.WriteLine("The LCID for {0} is {1}.", ci.Name, ci.LCID)

        ' Display the result using ja-JP Compare of coté < côte. 
        Console.WriteLine("ja-JP Compare: {0} {2} {1}", _
                          s2, s3, sign((ci.Compare(s2, s3) + 1)))
    End Sub 'Main
End Class 'App

' This code produces the following output.
' 
' The LCID for fr-FR is 1036.
' fr-FR Compare: Coté = coté
' fr-FR Compare: coté > côte
' The LCID for ja-JP is 1041.
' ja-JP Compare: coté < côte


.NET Framework

Supported in: 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Portable Class Library

Supported in: Portable Class Library

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
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